The original stackable growing pot tower arrangement was disclosed by Dov Orlov in U.S. Pat. No. 5,136,807 (1992), with an improved variation thereof disclosed in his U.S. Pat. No. 5,305,551 (1994). His first towers comprised vertically stacked growing pots formed into self-sustaining columns and an excess-fluid drain system, wherein water/nutrient introduced to the topmost pot and not used by plants passed downwardly through drain holes into the next lower pot, and so on, with any water/nutrient exiting the bottom growing pot being received by a drain system beneath it. Later Orlov improvements comprised a covered tank above multiple plant growing columns, and a fluid pumping system configured and positioned to provide fluid to the tank, which then drew metered amounts of fluid from the tank and directed it to emitters positioned above the topmost growing pot. Later Orlov towers also had a centrally-located and vertically-extending rigid tube employed for stabilizing the growing pots, which was also used to transport water and nutrients to the overhead emitters. Since their inception, Orlov towers have been used in many different ways to grow a wide variety of fruits and vegetables. Limited success was experienced relating to “home sales”, U-Pick Farms, and “Farm Stores”, particularly for the growing of strawberries which use far less water and nutrients than do other fruits and vegetables. Five and more stacked pots were often employed for strawberry production. However, the high tower arrangement used hindered commercial success, as significantly decreased crop yields were obtained in the lower stacked containers. Furthermore, when Orlov towers were tested for growing crops that use more water than strawberries, it was found they could not compete in cost with field cultivation methods used by large farming operations.
In an attempt to achieve greater success for his stacked growing pots over that experienced by Orlov, the inventor herein experimented and eventually discovered that the Orlov growing pot was too small for some crops. Also, the Orlov drain holes (four holes each ⅛-inch in diameter) were found to be too small, and too few in number, becoming easily plugged by growing media (which explained the lower production/yield routinely experienced in the lower stacked Orlov containers). The small Orlov growing pot also limited the size of transplant that could be used for certain crops, which further contributed to poor yields. In his continued attempts to grow more plants in less space, with less water and less fertilizer, the inventor herein has made many changes in his stacked growing pots that have progressively improved tower crop/plant production and yield. His continued testing and improvements extended growing pot life for longer reuse, and new materials discovered for growing pot manufacture created cost savings by allowing center holes to be custom-drilled to match the size of center support pipe used with it, and for the first time tower plant/crop cultivation became commercially viable and competitive with common field cultivation. In 1996, the inventor herein made growing pot improvements that involved a change in pot size, a change in the number of drainage holes per pot, and a change in the way his growing pots were stacked. These changes alone made it easier to stack and rotate the growing pots during their use, which made tower cultivation more efficient.
Subsequently, the inventor herein created another improvement for his growing pots. To provide easy tower rotation without damage to the stacked growing pots, he placed a thick opaque plate made from high-density polyethylene (HOPE) under the bottom growing pot in each tower to allow all stacked pots to rotate together. His experimentation with tower rotation improved plant growth on all sides of the tower, and produced a corresponding increase in growing pot life. A bottom support plate and spacer assembly also kept the bottom stacked growing pot in a tower from sinking into the ground as plant mass in the growing pots increased, and further use of a centered bottom hole with a diameter dimension of slightly more than 1-inch in each growing pot located in outdoor growing applications, allowed a sturdy steel pipe to extend through all growing pots in a tower, and then be driven into the ground to help protect tower integrity against damage from strong winds, driving rain, and other shearing forces. This arrangement placed about 48-inches of conduit above ground for tower construction, and allowed for a maximum of five growing pots to be stacked on a 4-inch riser separated by two rotation plates.
More recently, the inventor herein implemented additional improvements, which have further augmented the commercial viability of his towers, allowing them to increase crop yields without an increase in acreage. Such improvements include a simple, fast, and easy way to change the number of growing containers used in each tower according to the types of crops/plants to be grown therein, while concurrently maintaining a substantially uniform tower height among neighboring towers in a row so that one overhead nutrient distribution system may be used (without modification) for all towers in the row, even if the number of growing containers in adjacent tower is different to facilitate the growth of differing types of plants/crops. In addition, present invention growing pots have a new design configured to improve drainage and reduce shipping damage, and a modification to tower rotation has been made to accommodate the new container design. Protective sleeves made from hard material are also now positioned around growing pots in outdoor commercial applications to extend their life for longer repeat use. Experimentation with ground pots at the base of towers having less than a full complement of stacked growing pots also ensued to determine what type of bonus plants/crops could be successfully produced, as well as attempts at varying nutrient distribution into the top growing container in each tower. Furthermore, since multiple reuse of the present invention growing pots is needed for commercial success of tower plant/crop production, experimentation took place to find growing pot materials that were lightweight, yet sufficiently hard and strong to withstand repeated high-pressure washing with sodium hypochlorite solutions (used to remove old growing media and sterilize pots), and also withstand dipping in cleaning and/or sanitizing solutions used to reduce the risk of plant disease without contaminating growing media.
In addition to growing pot structure and design, the height of present invention towers are important to its commercial success, and the structure revealed herein for the present invention reduces the capital cost associated with tower plant growth by approximately 35%. Since present invention tower place approximately three times as many plants in the same square footage when compared to crops produced by prior art tower/column planting systems, planting and harvest time in present invention towers is substantially reduced over the prior art. Furthermore, as all bottom growing pots are typically at least 10-to-20-inches above the ground, workers require less bending to accomplish their tasks, making planting and harvesting much easier. Also, as a result of this above-ground elevation, certain crops (i.e. cucumbers and melons) can be grown above-the-ground and produce fruit without ground contact, thus eliminating soil-borne contamination of leaves and fruit. The raised positioning also allows less damage from small animals when towers are used outdoors, or in open-sided greenhouses. Furthermore, when fruit produced in present invention towers needs ground support, it can be further protected by placement of commercial ground cover and weed control fabric under the towers, which can be painted white in hot climates to reduce ground heat that might otherwise adversely affect fruit quality. No other plant tower growing system or method is known that functions in the same manner as the present invention, or provides all of its advantages.